EP2250140B1 - Article en céramique poreuse anisotrope et sa fabrication - Google Patents

Article en céramique poreuse anisotrope et sa fabrication Download PDF

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Publication number
EP2250140B1
EP2250140B1 EP09715548.5A EP09715548A EP2250140B1 EP 2250140 B1 EP2250140 B1 EP 2250140B1 EP 09715548 A EP09715548 A EP 09715548A EP 2250140 B1 EP2250140 B1 EP 2250140B1
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EP
European Patent Office
Prior art keywords
pore
long
matter
cross
alumina
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EP09715548.5A
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German (de)
English (en)
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EP2250140A1 (fr
Inventor
Monika Backhaus-Ricoult
Christopher R Glose
James W Zimmerman
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Corning Inc
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Corning Inc
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    • Y10T428/24997—Of metal-containing material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249981—Plural void-containing components
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/26—Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
    • Y10T428/268—Monolayer with structurally defined element

Definitions

  • This invention relates to ceramics and porous ceramic articles having anisotropic microstructure and methods of manufacture of the articles, and in particular low thermal expansion porous articles comprised of a polycrystalline ceramic comprising an anisotropic microstructure, such as can be used as a catalyst support or substrate or filter.
  • Aluminum titanate-based substrates typically in the form of a honeycomb body, have been used for a variety of applications such as catalytic substrates and filters for diesel particulate emission.
  • Document JP59-186623 A discloses a filter for purifying waste gas. To reduce the pressure loss and to make the filter small-sized without reducing the fine particle collecting efficiency of the waste gas filter by forming a cell of a ceramic porous body appearing in the cross section at right angles to the flow direction of a waste gas, into an elliptic shape.
  • a porous ceramic body is provided in accordance with independent claim 1.
  • a porous ceramic body is disclosed herein comprised of a polycrystalline ceramic comprising an anisotropic microstructure, the anisotropic microstructure being comprised of aligned polycrystalline multiphase reticular formations, and the porous body comprises aluminum titanate.
  • the reticular formations are comprised of microcrystals.
  • the reticular formations may be comprised of a primary solid phase and one or more minor solid phases.
  • the microstructure may further comprise portions that do not exhibit alignment along with the portions that exhibit the alignment.
  • an exterior region of the reticular formations being comprised of a primary solid phase and an interior region of the reticular formations being comprised of a minor solid phase.
  • the porous body has a porosity of greater than 40%; in other embodiments greater than 45%; in still other embodiments greater than 50%; in yet other embodiments greater than 55%; and in other embodiments, greater than 60%; and in other embodiments greater than 65%.
  • the porous body is shaped into a honeycomb structure.
  • a porous body comprising a polycrystalline ceramic comprised of an anisotropic microstructure, the anisotropic microstructure being comprised of aligned polycrystalline reticular formations comprising a primary solid phase of aluminum titanate.
  • the polycrystalline reticular formations are multiphase polycrystalline reticular formations.
  • an inorganic composition comprised of an anisotropic microstructure comprising the reaction product of a plurality of ceramic-forming precursors, wherein the reaction product is present as polycrystalline reticular formations.
  • the inorganic polycrystalline composition can advantageously comprise a low thermal expansion ceramic.
  • the ceramic is microcracked.
  • a method for forming a porous body comprised of a first ceramic phase of aluminum titanate, the method comprising: forming a plasticized mixture comprising a plurality of inorganic ceramic-forming precursors including a first precursor, wherein at least part of the first precursor is present in the mixture in the form of fibers; shaping the plasticized mixture into a green body; and heating the green body sufficient to cause the precursors to react and produce the first ceramic phase, wherein at least part of the first ceramic phase is comprised of a partially anisotropic microstructure comprised of polycrystalline reticular formations, and wherein at least some of the precursor fibers serve as templates for the reticular formations.
  • the overall morphology of the interlinked templates in the precursor material mixture is partially preserved during the high temperature reaction, in which the fibers provide precursor material that is converted into the first ceramic phase.
  • a portion of the precursor fibers reacts during the heating into the first ceramic phase, while an excess portion of the precursor fibers remains unreacted; in some of these embodiments, at least some of the excess portion is disposed in an interior region of at least some of the polycrystalline reticular formations.
  • Ceramic articles made in accordance herewith exhibit high strength, low coefficient of thermal expansion (CTE) and high porosity.
  • CTE coefficient of thermal expansion
  • the ceramic articles exhibit high thermal shock resistance through high fracture toughness, low thermal expansion, high strength, or low elastic modulus, or combinations thereof, and high filtration efficiency at low backpressure (due to high porosity, high pore interconnectivity, narrow pore size distribution, or small fraction of small pores, or combinations thereof).
  • a process for making highly porous low thermal expansion ceramic articles.
  • the process comprises steps of preparing a low expansion material forming batch (e.g. for forming low expansion aluminum titanate-based ceramic) comprising sources of particulate raw materials and at least one source of a fibrous raw material.
  • inorganic fibrous raw materials can include oxides of aluminum, silicon, magnesium, titanium, zirconium, and iron, and combinations thereof.
  • combinations for a feldspar-aluminum titanate composite can include sources of titania, alumina, silica, strontium oxide and optionally other additions or sinter additives.
  • Such inorganics can be mixed with organic pore formers, binders, lubricants or plasticizers, or combinations thereof, to obtain a plasticized (or "plastic") ceramic-forming mixture that is formed into a shaped article by, but not limited to, extruding through a die, for example into a honeycomb structure.
  • the method may further comprise drying and heating the shaped article at a temperature and for a time effective to convert the shaped article into the low thermal expansion ceramic article.
  • batch compositions comprising fibrous raw materials that produce an anisotropic ceramic microstructure and can provide high porosity, a narrow pore size distribution, desirable CTE, low elastic modulus, or high strength, or combinations thereof. Such properties can help to provide improved substrate or filter characteristics, such as low pressure drop, higher filtration efficiency and higher thermal shock resistance at high strength.
  • compositions disclosed herein are porous ceramics, advantageously having low thermal expansion, with an anisotropic microstructure.
  • a porous ceramic body can be comprised of a polycrystalline ceramic comprising an anisotropic microstructure, the anisotropic microstructure being comprised of aligned multiphase polycrystalline reticular formations.
  • the multiphase polycrystalline reticular formations comprise multiphase polycrystalline reticular formations that are aligned directionally, at least generally, for example in the direction of extrusion of a body formed by extrusion.
  • the majority of the multiphase polycrystalline reticular formations are aligned in a common direction.
  • the grains in the multiphase polycrystalline reticular formations in the anisotropic microstructure of the porous ceramic bodies disclosed herein can exhibit a preferential alignment.
  • the preferential alignment of the grains, or the preferential alignment of the reticular formations, or both, of the porous ceramic bodies disclosed herein can manifest in an anisotropy in porosity and/or matter distribution in the microstructure.
  • preferential alignment means that all, or fewer than all, of structures such as pores, grains or reticular formations are aligned in a particular direction; in some embodiments, the majority of such structures are aligned in a particular direction.
  • FIGS. 1a-1d show exemplary SEM images of the anisotropic microstructure of an exemplary aluminum titanate-feldspar composition obtained from fibrous alumina in the batch.
  • the low magnification image of FIG. 1a illustrates the anisotropic microstructure of the high porosity ceramic; the successive enlargements of the encircled area in FIGS. 1b and 1c show the polycrystalline nature and multiphase character of the reticular formations formed by solid state reaction during firing of a body formed from a batch mixture containing precursor fibrous raw material.
  • the aluminum titanate (AT) phase appears in grey, the strontium feldspar phase in white.
  • the chemical composition of the aluminum titanate phase in this example is 56 weight% alumina and 44 weight% titania, and the feldspar is a strontium feldspar with minor amounts of calcium and titanium.
  • the aluminum titanate adopted the orthorhombic pseudo-brookite structure, the strontium feldspar was triclinic. Small amounts of glassy phase in the material were also observed by transmission electron microscopy studies, but are not all visible in the SEM images of FIGS. 1a-1c due to the small size of the glass pockets.
  • the glass also contained aluminum, titanium, strontium, calcium, and lanthanum.
  • the SEM images further show that the ceramic is microcracked, wherein the thin black lines crossing aluminum titanate and feldspar grains in the figures are microcracks.
  • the anisotropic AT-based materials can also exhibit a grain morphology of the AT-grains comprising an elongated dumbbell-type features, as shown in FIGS. 1c-1d that can yield and which can allow for interlocking of the grains.
  • the compositions disclosed herein are produced by purposely including an excess amount of fibrous alumina precursor material in the batch.
  • Such compositions with excess alumina fiber can result in a similar microstructure as materials without any significant excess, in that the microstructure is anisotropic, containing multiphase polycrystalline reticular formations.
  • excess exists not all the fibrous alumina is reacted into the final reaction products (i.e. the excess alumina portion is not reacted), and a fraction of the alumina fibrous precursor from the batch remains unreacted in the final fired body.
  • excess fibrous alumina in a batch composition not all the fibrous alumina is reacted into the final reaction product, and a fraction can remain in the final material.
  • FIG. 2 is an SEM image of the anisotropic microstructure of a material obtained with fibrous alumina in the batch, wherein the batch included an excess of fibrous alumina.
  • FIG. 2 shows a detail of a wall of a polished honeycomb cross section perpendicular to the channel direction and perpendicular to the extrusion direction. The image shows a composite microstructure having unreacted portions of the precursor alumina fibers, with an alumina phase (dark grey contrast), that are surrounded by aluminum titanate (medium grey contrast). Strontium feldspar appears in light grey contrast in the images. Some triangular, small glass pockets can be seen in the feldspar phase. Microcracks are also visible in FIG. 2 as thin black lines.
  • Strength improvement of ceramics can be optionally achieved in some embodiments using an excess of fibrous raw material, such as fibrous alumina, in the batch, wherein it is believed, without being bound by any theory, that the unreacted portions of fibers in the material may act as an optional reinforcement for the composite and offer toughening of the material
  • low expansion ceramics with anisotropic microstructure disclosed herein are obtained by using a fibrous raw material in the batch that acts during the reactive sintering of the green ware as a microstructure template for the formation of the primary reaction product, so that the imprint of the shape of the fibrous raw material precursor is generally preserved and the reaction product grains grow into polycrystalline reticular formations that are interlinked into an anisotropic porous microstructure.
  • use of fibrous alumina precursor in the batch also imposes crystallographic texture of the aluminum titanate grains that form by solid reaction from the batch containing the fibrous alumina template.
  • a preferential crystallographic alignment has been observed of the crystallographic c-axis of aluminum titanate, which is herein defined as the negative expansion axis, while according to this definition a-axis and b-axis show positive expansion.
  • the c-axis of aluminum titanate aligns preferentially in the plane perpendicular to the compaction axis.
  • the aluminum titanate shows preferential crystallographic alignment of its c-axis in the direction of the extrusion (channel of the honeycomb).
  • the texture can be enhanced by a prealignment of the fibrous alumina raw material in the batch prior to the honeycomb extrusion, wherein very strong texture of c-direction of aluminum titanate in the direction of the honeycomb axis can be achieved.
  • batch material containing the fibrous alumina material can be extruded through a coarse die, for example resulting in a spaghetti-like extrudate, and that extrudate can then be further extruded in a similar extrusion direction, e.g. through a die imparting a honeycomb structure to the extrudate, wherein that extrudate is further formed into a green body that can be fired into a ceramic article.
  • texture can also be enhanced by using long precursor fibers as compared to using short precursor fibers. Texture can also be enhanced during mixing of the batch materials, such as the precursors and other raw materials, prior to extrusion with procedures that reduce mechanical solicitation so as to reduce breakage of the precursor fibers; in some embodiments, the lowest possible mechanical solicitation can be advantageous. Texture can also be enhanced by utilizing one or more apparatus that allows the precursor fibers to align before going through a forming die such as an extrusion die; for example, a twin screw extruder can help align the fiber before going through an extrusion die. MOR can be significantly improved in the alignment direction without major compromise of the MOR in directions perpendicular to the alignment direction as compared to particulate derived material.
  • the CTE of the material in this direction is very close to zero or negative, while in the direction perpendicular to the alignment the CTE is positive, and compared to particulate derived materials without any preferential alignment, more positive.
  • the elastic modulus of aluminum titanate-feldspar composites increases with increasing temperature and shows a significant hysteresis between heating and cooling cycles.
  • the material made with fibrous alumina e.g. CT4 in Fig. 2A , filled diamonds - heating, hollow diamonds - cooling
  • CT4 in Fig. 2A filled diamonds - heating, hollow diamonds - cooling
  • the quantity or length of the microcracks are reduced or are associated with different levels of microcrack energy than in corresponding materials obtained from particulate alumina.
  • Some examples of aluminum containing fibrous materials that can be used in the ceramic-forming batch mixture include alumina, alumino-silicates, aluminum titanate, and magnesio-alumino-silicates.
  • fibers having a composition of 96-97% Al 2 O 3 and 3-4% SiO 2 with median fiber length 3 mm and diameter 3-25 micrometers were used as fibrous raw material. These compositions and dimensions of the fibers are only exemplary, not limiting. Other fiber dimensions or compositions can be used.
  • exemplary aluminum titanate-feldspar ceramic composites For the preparation of exemplary aluminum titanate-feldspar ceramic composites, the following batch materials were used in different combinations as source for alumina: coarse particulate alumina with average particle size of about 10 ⁇ m and broad particle size distribution, fine particulate alumina with average size of 1 ⁇ m or less and broad particle size distribution, hydrated alumina and alumina fiber.
  • the batch ingredients further included fine titania with submicrometer particle size, coarse or fine silica and coarse strontium carbonate.
  • the batch also included pore formers, namely coarse starch such as potato starch, or fine starch such as corn starch, and/or graphite, which yield different pore sizes, coarse starch leading to larger pores than fine starch.
  • Exemplary raw material characteristics for aluminum titanate- feldspar batches are listed in Table 1.
  • TABLE 1 Specifications of raw material used in exemplary AT-based batches
  • Raw Material Abbreviation Median Particle Diameter ( ⁇ m) Coarse Silica S1 10 Fine Silica S2 4-6 Coarse Alumina A 10-25 Fine Alumina B 0.1-3 Rutile 0.1-5 Lanthanum Oxide 0.1-10 Alumina, hydrate 1-10 Strontium Carbonate 5-20 Calcium Carbonate 5-20 Alumina fiber F1 2-30 diameter, 50-3000 length Alumina fiber F2 5-10 diameter, 200-1000 length Alumina fiber F3 3-20 diameter, 50-1000 length Pore Former Fine starch (e.g. corn starch) CS 10-20 Large starch (e.g. potato starch) PS 25-50 Graphite 30-50
  • Exemplary batch compositions are listed in TABLE 2 for forming the aluminum titanate-feldspar composites. Batch compositions were chosen that yielded a mixture of aluminum titanate and feldspar in the approximate range of 3.5 : 1.
  • TABLE 2 Batch compositions for AT-based materials Code %fiber alumina type %alumina particulate %hydrated alumina particulat e %SiO2 %SrCO3 %CaCO3 %TiO2 %La2 O3 % Pore former as superaddition Pore former A16 48.01 na 0.00 3.71 8.75 8.00 1.38 29.95 0.20 0.00 CS B1 15.00 A 36.87 3.71 9.89 8.00 1.38 29.95 0.20 15.00 CS B2 20.00 A 27.17 3.71 9.59 8.00 1.38 29.95 0.20 15.00 PS B3 10.00 A 37.17 3.71 9.89 8.00 1.38 29.95 0.20 15.00 PS B4 10.00 A 37.17 3.71 9.89 8.00 1.38 29.95 0.20
  • CS corn starch
  • PS potato starch
  • g graphite
  • A coarse alumina powder with median particle size between 10 and 15 micrometer
  • B is a fine alumina with submicrometer median grain size
  • % are given in % of inorganics with pore formers (potato starch, cornstarch and graphite) being reported as superaddition to the inorganics.
  • Extrusion batches typically contained a water level of about 30%. Some batches contained additional lubricants.
  • Low expansion ceramics with anisotropic microstructure as disclosed herein were obtained by different forming processes.
  • a slurry of the raw materials can be pressed into a form.
  • a paste of the raw materials (including binder and water) can be extruded into a honeycomb shape e.g. by using a ram extruder or a twin screw extruder or a combination of both.
  • one or more apparatus may. be used to align precursor fibers prior to extrusion through an extrusion die, such as a ram extruder with a coarse die that yields spaghetti-like extrudate that can be subsequently input into an extruder with a finer die.
  • the resulting shaped body i.e. green ware, can be dried and then fired. During firing, the inorganic raw materials, including fibrous precursor, are reacted, or converted, into the final ceramic product.
  • the batch composition A16 as indicated in TABLE 2 used fibrous raw material of composition 97% Al 2 O 3 and 3% SiO 2 with fiber average length 3.2 mm and average diameter 3 micrometer.
  • the fibers were incorporated into the batch by three-axis rotational dry mixing for 30 minutes.
  • An addition of 14 weight percent water and 1% surfactant (Pluronic F127, BASF) was mixed into the batch using ball milling for two hours with alumina milling media. Excess liquids were decanted and pellets (wet) were punch pressed using a pressure of 5 MPa. The pellets were microwave dried and re-pressed with a pressure of 15 MPa. Pellets were reaction sintered with final temperatures between 1390° and 1440°C.
  • the final composition contained alumina titanate, feldspar and residual amounts of alumina and titania. Peak intensity ratios in the X-ray diffraction pattern showed in the pressed pellet a preferential alignment of the aluminum titanate crystallographic c-axis in the plane perpendicular to the pressing direction.
  • the SEM image shows that the reaction products aluminum titanate and feldspar align perpendicular to the pressing direction into polycrystalline reticular formations forming an anisotropic microstructure with incorporated directional porosity, as seen, for example, in FIGS. 4a & 4b .
  • the anisotropic microstructure was composed of polycrystalline reticular formations comprised of both aluminum titanate and feldspar small grains.
  • the crystallographic c-axis of the aluminum titanate grains that is associated with the negative thermal expansion coefficient was preferentially aligned in the pressing plane.
  • Forming Example 2 Extruded honeycomb comprised of anisotropic AT-feldspar composite (RAM, twin screw)
  • Honeycomb porous ceramics with anisotropic microstructure were made by RAM and twin screw extrusion.
  • the powderous batch ingredients, pore former and binder were premixed. Dry ingredients were combined in a mulling pan and mulled, while fibrous alumina and batch water were either slowly added to the muller mixture, and mixed, or pre-mulled to break the fiber interlinked network up into a powder-like mix of short fibers, that was then added with the other raw materials into the muller. Distilled water was added during mulling until a suitable paste texture was reached.
  • a RAM extruder was used for pre-extruding the paste into rods of 9 mm diameter or spaghetti of 1 mm diameter in a first and second run in order to improve the uniformity and plasticity of the batch material.
  • the paste was then extruded on a RAM extruder into a honeycomb shape with a honeycomb die and shim of appropriate size.
  • RAM extrusions were performed with a die geometry (200/16) with 31 cells/cm 2 (200 cells per square inch) and a wall thickness 406 ⁇ m (16 mil) to provide 25.4 mm (1") diameter extruded parts.
  • Green ware with different ratios of fibrous to particulate raw batch materials were extruded. In all cases, excellent green ware was obtained.
  • continuous feed twin screw extrusions were performed with a die geometry (300/14) with 46.5 cells/cm 2 (300 cells per square inch) and an extruded wall thickness 356 ⁇ m (14 mil) to provide 50.8 mm (2") diameter honeycomb diameter extruded parts.
  • extruded green honeycomb parts were dried in a microwave oven at medium power for 5 minutes and then further dried in a drying oven for 24 hours at 85 °C.
  • FIGS. 3a-3b show SEM micrographs of polished longitudinal section and cross-section, respectively, of a honeycomb wall of an as-extruded, dried and unreacted (green) ware formed from Batch 10 obtained with fibrous alumina raw material in the batch, illustrating a preferential alignment of the alumina fibers in the direction of the extrusion in the greenware.
  • Extruded parts of 102 to 254 mm (4 to 10") lengths were fired after drying in a furnace in air using a heating rate of 120°C/h to the maximum firing temperature indicated in TABLE 5, which ranged from 1390 °C to 1440°C, a hold for 15 hours and cool down rate of about 60°C/hour.
  • Strength of partially fired parts was significantly improved where the fibrous alumina raw material was included in the batch. In the temperature range from 400°C -800°C, the firing strength was improved by a factor of at least 10 when substituting particulate alumina in the batch with alumina fibers.
  • the fully fired materials from AT batches contained aluminum titanate, feldspar and residual amounts of alumina, mullite and titania.
  • the primary product phase was in all cases aluminum titanate.
  • the phase contents of various compositions can be found in TABLE 5.
  • the microstructure of the materials obtained from fibrous alumina raw material in the batch was for all forming conditions anisotropic, and the degree of anisotropy depended upon the ratio of particulate to fibrous alumina raw material, wherein the more fibrous material present in the batch, the more anisotropic the resulting microstructure.
  • FIGS.4a-4n show views of various honeycomb wall microstructures for materials obtained with different ratios of particulate to fibrous alumina raw material and by different forming processes.
  • FIG. 4a is an SEM photomicrograph of an as-fired pellet surface of comparative ceramic A16 obtained from fibrous alumina raw material by compaction.
  • FIG. 4b is an SEM photomicrograph of a polished wall longitudinal section parallel to the direction of compaction force of ceramic A16 obtained from fibrous alumina raw material by compaction.
  • FIG. 4c is an SEM photomicrograph of an as fired honeycomb wall surface of ceramic C4 obtained from fibrous alumina raw material by RAM extrusion.
  • FIG. 4d is an SEM photomicrograph of a polished honeycomb wall cross section of ceramic C4 obtained from fibrous alumina batch raw material by RAM extrusion.
  • FIG. 4e is an SEM photomicrograph of a polished honeycomb wall longitudinal section of ceramic C4 obtained from fibrous alumina raw material by RAM extrusion.
  • FIG. 4f is an SEM photomicrograph of an as fired honeycomb wall surface of ceramic CT1 obtained from fibrous alumina batch raw material by twin screw extrusion.
  • FIG. 4g is an SEM photomicrograph of a polished honeycomb wall cross section of ceramic CT1 obtained from fibrous alumina batch raw material by twin screw extrusion.
  • FIG. 4h is an SEM photomicrograph of a polished honeycomb wall longitudinal section of ceramic CT1 obtained from fibrous alumina batch raw material by twin extrusion.
  • FIG. 4i is an SEM photomicrograph of an as fired honeycomb wall surface of ceramic B1 obtained from fibrous and particulate alumina batch raw material in approximate ratio 1:2 (see Table 2) and with alumina excess by RAM extrusion.
  • FIG. 4j is an SEM photomicrograph of a polished honeycomb wall cross section of ceramic B1 obtained from fibrous and particulate alumina raw material in ratio 1:2 and with alumina excess by RAM extrusion.
  • FIG. 4k is an SEM photomicrograph of a polished honeycomb wall longitudinal section of ceramic B1 obtained from fibrous and particulate alumina batch raw material in ratio 1:2 and with alumina excess by RAM extrusion.
  • FIG. 4i is an SEM photomicrograph of an as fired honeycomb wall surface of ceramic B1 obtained from fibrous and particulate alumina batch raw material in approximate ratio 1:2 (see Table 2) and with alumina excess by RAM extrusion.
  • FIG. 4j is an SEM photomicrograph of a polished honeycomb wall cross section of ceramic B1 obtained from fibr
  • FIG. 4l is an SEM photomicrograph of an as fired honeycomb wall surface of ceramic P2 obtained from coarse particulate alumina raw material by RAM extrusion.
  • FIG. 4m is an SEM photomicrograph of a polished honeycomb wall cross section of ceramic P2 obtained from coarse particulate alumina batch raw material by RAM extrusion.
  • FIG. 4n is an SEM photomicrograph of a polished honeycomb wall longitudinal section of ceramic P2 obtained from coarse particulate alumina raw material by RAM extrusion.
  • FIG. 4o is a schematic drawing showing (A) a section in a plane perpendicular to the direction of compaction and (B) a section in a plane parallel to the direction of compaction (arrow), of a pressed or compacted comparative pellet such as by RAM extrusion.
  • FIG. 4p is a schematic drawing showing (A) a section in a plane perpendicular to the direction of extrusion and (B) a section in a plane parallel to the direction of extrusion (arrow), of an extruded part (e.g. honeycomb structure), such as by twin screw extrusion.
  • an extruded part e.g. honeycomb structure
  • the properties of various materials were evaluated with various techniques and procedures.
  • the phases present in the fired ceramic parts were identified by X-ray diffraction (XRD).
  • XRD X-ray diffraction
  • Philips PW1830 diffractometer Co K ⁇ radiation
  • Spectra were typically acquired from 20 to 100° (20).
  • Rietveld refinement was used for quantification of the phase contributions.
  • Standard scanning electron microscopy, SEM, characterization was conducted on honeycomb wall surfaces and polished honeycomb wall longitudinal cross sections (cut in the direction of the honeycomb channels) and polished honeycomb cross sections (cut perpendicular to the honeycomb channels). For the observation of polished sections, the fired ware was infiltrated with epoxy, sliced and polished. The spatial distribution of porosity and phases in presence at a microscopic level was visualized on polished sample cross sections. The material porosity was evaluated by SEM image treatment techniques, listed in Table 5 as PSEM in %. PSEM was used to determine the spatial anisotropy in the porosity distribution. SEM image treatment also provided an average pore size daverage.
  • pore-surf/vol average pore surface/pore volume ratios
  • SEM was also used to acquire images of the pore shape distribution, which was then quantified to derive a pore anisotropy factor for the porosity.
  • High resolution SEM was used to assess details of the anisotropic microstructure and the phase distribution.
  • porosity, median pore diameter and pore size distribution corresponds to measurements determined with a mercury intrusion porosimeter. Values reported herein were obtained from an Autopore IV 9500 porosimeter with software from Micromeritics.
  • the mercury porosity data can further be used to deduce a tortuosity.
  • the tortuosity factor characterizes the efficiency of gas interaction with the surface during its transport through a porous medium.
  • Tortuosity is strongly dependent on the pore interconnectity.
  • the gas interaction with the material internal surface is the higher the larger the tortuosity factor is.
  • J. Hager (PhD thesis, Lund University, Sweden 1999 ) derived an expression for material permeability based on a capillary bundle model in which pores are homogeneously distributed in random directions.
  • Hagen-Poiseuille correlation for fluid flow in cylindrical geometries, and making substitutions with measurable parameters, and combining with Darcy's law, an expression can be derived for material permeability in terms of total pore volume, material density, pore volume distribution by pore size, and material tortuosity.
  • the total pore volume, material density, and pore volume distribution by pore size are obtainable from mercury porosimetry tests.
  • Katz and Thompson also derived an expression for material permeability based on measurements obtainable from mercury porosimetry and which does not depend on knowledge of material tortuosity. Combining the Hager and Katz-Thompson expressions provides a means for determining tortuosity from data collected by mercury porosimetry
  • Thermal expansion was measured for bar-shaped samples with dimension 6.35 x 6.35 x 50.8 mm (0.25" x 0.25" x 2”) during heating from room temperature to 1200°C at a rate of 4C/min and subsequent cooling to room temperature. Unless otherwise noted herein, the longitudinal axis of the test bars was oriented in the direction of the honeycomb channels, thus providing the thermal expansion in the axial direction of the honeycomb parts. Unless otherwise noted herein, room temperature as stated herein refers to 25 °C.
  • Average thermal expansion coefficients for various temperature ranges are listed in Table 5, CTE 20-800 in K -1 , the average thermal expansion coefficient from room temperature to 800C, defined as L(800°C)-L(20°C)/780°C as average thermal expansion coefficient in the temperature range from room temperature to 800°C, CTE 20-1000 in K -1 , the average thermal expansion coefficient from room temperature to 1000°C, defined as L(1000°C)-L(20°C)/980°C as average thermal expansion coefficient in the temperature range from room temperature to 1000°C, CTE 500-900 in K -1 , the average thermal expansion coefficient from 500 to 900°C, defined as L(900°C)-L(500°C)/400°C as average thermal expansion coefficient in the temperature range from 500°C to 800°C.
  • CTE 500-900 can be a relevant parameter for evaluating or characterizing ceramic articles and in particular honeycomb parts for exhaust after treatments in the automotive vehicle, where the honeycomb part is subjected to severe rapid temperature changes and thus the temperature range from 500-900°C would represent a frequently encountered operation temperature range for such parts.
  • the strength of a ceramic can be tested using a transverse bending technique where test specimens are loaded to failure in using either three or four bending points.
  • the maximum stress prior to failure is often referred to as the modulus of rupture or MOR.
  • strength values are reported herein using a 4-point flexure. MOR, measured using four point flexure with a lower span (L) of two inches (fifty and four fifths millimeter) and an upper span (U) of three quarters of an inch (nineteen millimeters).
  • the specimen geometry for the 4-point flexure tests was two and one half inches (sixty three and one half millimeters) in length, one half inch (twelve and seven tenths millimeters) in width (b) and one quarter inch (six and two fifths millimeters) thick (d).
  • the force-measuring system used was equipped with a read-out of the maximum force (P) and a calibrated load cell.
  • the MOR value was calculated using the well known flexure strength equation (Equation 1) for a rectangular specimen.
  • Equation 1 the well known flexure strength equation
  • P the maximum force
  • L the lower span length
  • b the width of the test bar
  • d the thickness of the test bar
  • m the number of cells in the width direction
  • n is the number of cells in the thickness direction
  • t is the wall thickness
  • p is the cell pitch. See ASTM standard C1674-08.
  • FIG. 6 indicates the parameters used in the equation used to assess the wall strength.
  • the elastic modulus obtained in a heating and a cooling cycle for microcracked ceramics shows an extensive hysteresis that is related to the fact that during heating to temperatures above about 700°C microcracks in the material start to close, which yields an increase in the elastic modulus during heating in the temperature range from about 700°C to 1200°C. At around 1200°C, a portion of the microcracks is typically already closed in the aluminum titanate-based materials, and ceramic with lesser microcracks is obtained.
  • the elastic modulus curve follows initially that of the ceramic with partially closed microcracks and thus a lowered microcrack density, characterized by a straight line with a slightly negative slope, the slope of which is determined by the intrinsic elastic modulus of the ceramic with the lowered microcrack density.
  • a critical local stress is reached during cooling, further microcracks start to form and/or reopen during further cooling.
  • the onset of additional microcracking during cooling is observed in the elastic modulus cooling curve for temperatures below 900°C.
  • the elastic modulus then decreases with decreasing temperature, reflecting increasing microcracking.
  • the elastic modulus of the cooling curve finally reaches the original starting value of the heating curve, which is the room temperature elastic modulus of the microcracked ceramic Emc RT .
  • the degree of hysteresis between the heating and cooling elastic modulus curves reflects the microcrack density change of the material at room temperature and the material at 1200C.
  • elastic modulus (EMOD) data is reported herein at room temperature (at 25 °C): EMOD RT , at high temperature (1000 C): EMOD 1000C , or at different temperatures during cooling.
  • Strain tolerance can be derived from the strength of the material and its Young's modulus in order to describe the ability of a material to handle strain. The higher the strain tolerance, the less likely the material will fracture.
  • the strain tolerance is independent of the honeycomb geometry and can directly be compared for parts with different cell densities or wall thickness. As used herein, for same cell and wall geometry the strain tolerance is proportional to MOR divided by EMOD, which is dimensionless, and is in the tables evaluated for room temperature.
  • the resistance to thermal shock can be a meaningful parameter for evaluating or characterizing a honeycomb part meant for exhaust after-treatment because the part undergoes severe thermal cycling during rapid heat up and cool down.
  • the thermal shock resistance of a honeycomb structure improves with higher strength, lower elastic modulus and/or lower thermal expansion of its material.
  • the anisotropic material disclosed herein can possess anisotropy in matter, or anisotropy in porosity, or both.
  • a quantification method of anisotropy in matter and porosity spatial distribution within a honeycomb cell wall is presented below.
  • Characteristic numbers for the anisotropic distribution of matter and porosity have been derived from SEM images of polished wall long and wall cross sections.
  • Sample preparation Polished wall cross sections of fired, extruded honeycomb parts were obtained by infiltrating the honeycomb with epoxy, cutting the honeycomb perpendicular to the extrusion direction (honeycomb axis) and polishing the cut surface with a diamond medium to a final polish of 3 micrometers.
  • Polished wall long sections of fired, extruded honeycomb parts were obtained by cutting out a single wall of the honeycomb, infiltrating the honeycomb with epoxy, grinding the honeycomb down to half of its thickness and polishing the honeycomb with a diamond medium to a final polish of 3 micrometers.
  • Image acquisition in the SEM The polished wall cross and long sections were imaged by scanning electron microscopy (SEM) by backscattered electrons (BSE) using an acceleration voltage of 25 KV. For both sections, images were acquired at a magnification of 150 times with an image resolution of at least 0.795 ⁇ m per pixel and an accuracy of ⁇ 2 pixels (1.590 ⁇ m) in image size.
  • Each image was scanned using an (840x2) pixels x (360x2) pixels scanning area of interest. 180 scan lines across the web and 360 scan lines along the web were taken.
  • Image treatment procedure An image treatment program such as, for example, Image Pro, can be used and applied to the selected area on each image.
  • the area is chosen so that it is within the inside of the polished wall section and does not include the wall surface.
  • the area is also chosen to be not a web cross section.
  • the image definition is chosen to be at least (840x2) pixels x (360x2) pixels.
  • the area is spanned by an x-direction and a y-direction. Results reported below were obtained using Image Pro image treatment program.
  • the selected image area is divided in the direction perpendicular to that direction 1 into bands of 2 pixels in width.
  • the bands are adjacent, do not overlap and their sum covers the entire image.
  • the length of all individual pore and matter (solid) segments is measured (using black-white contrast distinction in the image treatment). This is repeated for all bands.
  • the length of each individual pore segment in the image is reported in a distribution plot of the pore length on the cross section in direction 1. The distribution is characterized by a mean pore length in the direction 1, d50pore-cross-dir 1.
  • x can be, for example, a value from 1 to 99 (and not just "d50").
  • the length of each individual matter segment in the image is reported in a distribution plot of the matter segment length on the cross section in directionl.
  • the distribution is characterized by a mean matter segment length in the direction 1, d50matter-cross-dir1.
  • the procedure is repeated in the direction perpendicular to direction 1, i.e. direction 2, on the cross sectional image to determine the cross sectional- direction 2- factors.
  • direction 2 the length of each individual pore segment in the image is reported in a distribution plot of the pore length on the cross section in direction 2
  • the length of each individual matter segment in the image is reported in a distribution plot of the matter segment length on the cross section in direction 2.
  • the pore segment length distribution is characterized by a mean pore length in the direction 2, d50pore-cross-dir2. Other characteristics of the distribution can also be derived such as the width of the distribution and other dx, where x can be, for example, a value from 1 to 99 (and not just "d50").
  • the matter segment length distribution is characterized by a mean matter segment length in the direction 2, d50matter-cross-dir2.
  • the selected image area is divided in the direction perpendicular to the extrusion direction, which is the honeycomb long axis and the wall long axis into bands of 2 pixels in width.
  • the bands are adjacent, do not overlap and their sum covers the entire image.
  • the length of all individual pore and matter (solid) segments is measured (using black-white contrast distinction in the image treatment). This is repeated for all bands.
  • the length of each individual pore segment in the image is reported in a distribution plot of the pore length on the long section in extrusion direction. The distribution is characterized by a mean pore length in the direction of extrusion, d50pore-long-extrdir.
  • x can be, for example, a value from 1 to 99 (and not just "d50").
  • the length of each individual matter segment in the image is reported in a distribution plot of the matter segment length on the long section in extrusion direction.
  • the distribution is characterized by a mean matter segment length in the extrusion direction, d50matter-long-extrdir.
  • the procedure is repeated in the direction perpendicular to extrusion direction, perpextr, on the long sectional image to determine the long sectional- perpextr direction-factors.
  • the length of each individual pore segment in the image is reported in a distribution plot of the pore length on the long section in direction perpendicular to the extrusion and the length of each individual matter segment in the image is reported in a distribution plot of the matter segment length on the long section in the direction perpendicular to the extrusion.
  • the pore segment length distribution is characterized by a mean pore length in the direction perpendicular to the extrusion, d50pore-long-perpextrdir. Other characteristics of the distribution can also be derived such as the width of the distribution and other dx, where x can be, for example, a value from 1 to 99 (and not just "d50").
  • the matter segment length distribution is characterized by a mean matter segment length in the direction perpendicular to the extrusion, d50matter-long-perpextrdir.
  • the four ratios Af-matter-long, Af-pore-long, Af-matter-cross, Af-pore-cross are all equal to 1.
  • Anisotropy in the matter distribution is characterized by a deviation from 1 of the factors Af-matter-long or Af-matter-cross. The larger the deviation from 1, the larger is the anisotropy.
  • Anisotropy in the spatial distribution of the porosity is characterized by a deviation from one of the factors Af-pore-long or Af-pore-cross. The larger the deviation from 1, the larger is the anisotropy.
  • a simplified illustration can be provided by a material with a set of individual pores having a simple shape. For example, for spherical pores, the porosity is isotropic with the anisotropy ratios being 1 in both directions.
  • the porosity distribution in space becomes anisotropic and the ratios deviate from 1
  • the anisotropy and the deviation from 1 is larger the more the ellipsoids are preferentially aligned in space and the larger the average aspect ratio of the ellipsoids is.
  • both anisotropic microstructure and crystallographic texture of grains with anisotropy in their thermal lattice expansion help to provide high toughness to the part and help to reduce the propagation of cracks and formation of macrocracks.
  • the following tables show the high strength of the material disclosed herein.
  • Table 3 shows examples of ceramic articles formed by 1" ram extrusion and subsequent firing from particulate alumina (no fiber) batches.
  • Table 3 Example No. P1 P2 P3 P4 type of alumina raw material in batch Particulate A1 Particulate A1 Particulate A1 Particulate A1 batch fiber content % (of inorganic oxides) 0 0 0 0 excess alumina fiber in batch (%) (compared to particulate alumina batch P1) 0 0 0 0 0 Firinq temperature (°C) 1410 1410 1410 1410 Hold time ( hours ) 15 15 15 15 15 15 Cell Density 169 169 169 Wall Thickness (10 -3 inches) 16 16 16 16 16 CFA 0.373 0.373 0.373 0.373 % Porosity 29.3 51.81 48.40 50.81 d1 (um) 0.15 3.87 0.65 1.95 d2 (um) 0.25 7.11 5.42 4.48 d5 (um) 0.53 8.79 8.10 7.
  • Table 4 shows examples of properties of ceramic honeycomb extruded by 25.4 mm (1") ram extrusion from batches with mixed particulate and fibrous alumina.
  • Table 5 lists examples of properties of ceramic honeycomb extruded by 1" ram extrusion from batches with fibrous alumina (no particulate), CS pore former.
  • C1 had no pore former in the batch.
  • C4-C6 had an excess amount of alumina fiber in the batch.
  • Table 6 shows additional examples of properties of ceramic honeycomb extruded by 1" ram extrusion from batches with fibrous alumina (no particulate), CS pore former.
  • C9 and C10 had higher levels of corn starch.
  • Table 6 Example No. C7 C8 C9 C10 type of alumina raw material in batch Fibrous F1 Fibrous F1 fibrous F1 Fibrous F1 batch fiber content % (of inorganic oxides) 51.57 48.01 48.01 48.01 excess alumina fiber in batch (%) (compared to particulate alumina batch compo) 3.56 Firing temperature (°C) 1410 1410 1410 1410 Hold time ( hours ) 15 15 15 15 15 15 Cell Density 169 169 169 169 Wall Thickness (10 -3 inches) 16 16 16 16 16 16 CFA 0.373 0.373 0.373 0.373 % Porosity 59.11 58.90 60.80 d1 (um) 2.69 3.14 4.04 d2 (um) 3.
  • Table 7 shows examples of properties of ceramic honeycomb extruded by 25.4 mm (1") ram extrusion from batches with fibrous alumina (no particulate), PS pore former. Various PS pore former levels were used. Table 7 Example No. C11 C12 C13 C14 C15 type of alumina raw material in batch fibrous F1 fibrous F1 fibrous F1 fibrous F1 fibrous F1 batch fiber content % (of inorganic oxides) 48.01 48.01 48.01 48.01 48.01 excess alumina fiber in batch (%) (compared to particulate alumina batch compo) Firing temperature (°C) 1410 1410 1410 1410 1410 Hold time (hours) 15 15 15 15 15 Cell Density 169 169 169 169 Wall Thickness (10 -3 inches) 16 16 16 16 16 CFA 0.373 0.373 0.373 0.373 % Porosity 61.14 60.77 65.51 69.07 d1 (um) 2.92 3.93 3.74 7.17 d2
  • Table 8 shows examples of properties of ceramic honeycomb extruded by 25.4 mm (1") ram extrusion from batches with fibrous alumina (no particulate), PS pore former.
  • C16 included tall oil in the batch, and was not sieved.
  • C 17 had fiber excess in the batch.
  • the fiber was pre-mulled.
  • C18 and C19 the fibers were different length (C19 was a long fiber) in the batch.
  • C20 used no hydroxide.
  • C21 yielded 3% feldspar. Table 8 Example No.
  • Table 9 shows further examples of properties of ceramic honeycomb extruded by 25.4 mm (1") ram extrusion from batches with different types of fibrous alumina (no particulate), PS pore former.
  • Table 9 Example No. D1 E1 F1 type of alumina raw material in batch fibrous alumina F2 part+fib F1 part+fib F3 batch fiber content % (of inorganic oxides) 48.01 20.38 40.76 excess alumina fiber in batch (%) (compared to particulate alumina batch compo)
  • Table 10 shows further examples of properties of ceramic honeycomb extruded by 25.4 mm (1") ram extrusion from batches with different types of fibrous alumina (no particulate), PS pore former, formed with thinner walls.
  • Table 10 F1 fiber F1 fiber F1 fiber Example No.
  • Table 11 shows Examples of 50.8 mm (2") diameter ceramic honeycomb articles formed via twin screw extruder.
  • the MOR values provided in the table are averages based on a number of MOR measurements.
  • CT6 utilized a long batch milling time in a Littleford mixer before extrusion.
  • Table 11 Example No.
  • Table 12 shows further examples of 50.8 mm (2") diameter ceramic honeycomb articles formed with fibrous raw material via twin screw extruder using the same batch but differing firing temperatures.
  • Table 12 Example No. CT1 CT1 CT1 Firing temperature (°C) 1405 1410 1425 Hold time ( hours ) 15 15 15 Green Cell Density 288 288 288 Green Wall Thicknes s (10 -3 inches) 14 14 14 Green CFA 0.419 0.419 0.419 % Porosity 58.76 57.59 58.21 d1 (um) 4.01 5.58 3.17 d2 (um) 5.10 6.45 5.99 d5 (um) 6.79 7.73 8.34 d10 (um) 8.37 9.14 9.96 d25 (um) 11.04 11.53 12.41 d50 (um) 13.69 13.82 14.70 d75 (um) 15.83 15.95 17.15 d90 (um) 24.05 23.41 23.30 d95 (um) 62.84 59.12 53.04 d98 (um) 165.
  • Table 13 shows further examples of thin wall 2" diameter ceramic honeycomb articles made with fibrous raw material and formed via twin screw extruder.
  • Example CT3 utilized 15% corn starch in the batch, and extrusion was through a twin screw extruder to form a thin wall 2" diameter honeycomb having 62 cells/cm 2 (400 cells per square inch) and 203 ⁇ m (8 mil) (0.008 inch) wall thickness webs.
  • CT4 utilized 15% potato starch in the batch, and extrusion was through a twin screw extruder to form a thin wall 50.8 mm (2") diameter honeycomb having 400 cells per square inch and 8 mil (0.008 inch) wall thickness webs.
  • Table 13 Example No.
  • embodiments of the batches disclosed herein are capable of yielding high porosity. Even without any pore former in the batch, parts with 46% porosity at a median pore size of 9 micrometers were obtained with alumina fiber in the batch e.g. Example C1. Addition of only 15% corn starch as pore former allowed porosity to reach 60% in the fired ware with an average pore size in the range of 12-15 micrometers, such as Examples C2-C8. Use of 15% potato starch instead of corn starch in the batch yielded a larger average pore size, in the range of 15-17 micrometers at about 55-60% porosity, such as Examples C12, C16, and C18-C20. Addition of 50% potato starch provided high porosity, for example 69%, for Example C15.
  • FIG. 7 is a schematic plot of the pore size distributions of various materials disclosed herein illustrating a broad range of median pore sizes at narrow pore size distribution with the materials disclosed herein.
  • FIG. 7 shows materials as disclosed herein with porosity between 50 and 62% that have all been obtained with 15% pore former (B1 - potato starch; B6, C5, CT1, B8 - corn starch) and with various levels of fibrous alumina and different sizes of particulate alumina.
  • the plot demonstrates that high porosity materials as disclosed herein having anisotropic microstructure can be provided by selecting from a wide range of median pore size distributions achievable as disclosed herein.
  • anisotropic materials made with potato starch can provide median pore sizes in the range from 12 to 25 micrometers, which can be suitable for diesel particulate filters, and anisotropic materials made with cornstarch and coarse alumina or very low levels of particulate alumina can provide very high porosity materials with pore sizes ranging from 10-15 micrometers, which can be useful in diesel particulate filter applications because of high porosity and pore interconnectivity.
  • Materials as disclosed herein can provide porosity of more than 50% or even more than 60%, and even greater than 65%, and in some embodiments greater than 68%, and such materials can be utilized in applications such as automotive substrates, diesel or gasoline particulate filters and in functionalized filters such as catalyzed filters with integrated partial or full NOx conversion.
  • porosity as function of concentration of fibrous alumina in the batch together with coarse particulate alumina, demonstrating a range in porosity obtainable, all using the same amount of pore former (i.e. 15% potato starch or corn starch)
  • porosity > 50% when less than 25% raw material fiber was used in the batch.
  • porosity > 55%, and even > 60%, when greater than 45% raw material fiber was used in the batch.
  • the materials disclosed herein exhibited narrow pore size distributions. In particular, the contribution of very large and very small pores was significantly lowered in the anisotropic materials disclosed herein.
  • the d-factor can be a useful indicator for applicability of a material for use of catalyst in a filter; the lower the value the generally more suited is a substrate for hosting a catalyst and using it efficiently.
  • pore network characteristics such as the width of the pore size distribution (d90-dlO)/d50 or the permeability, which both provide indication on the back pressure of the uncoated substrate.
  • Low pressure drop is enhanced by high porosity and a narrow pore size distribution and large pore size; filtration efficiency is enhanced by a narrow pore size distribution with small pore size.
  • the materials disclosed herein exhibited high wall permeability, and as compared to the corresponding products obtained with particulate raw materials, they showed higher permeability at a smaller average pore size and narrower pore size distribution, useful for combining the advantages of low pressure drop and high filtration efficiency.
  • the materials disclosed herein preferably contain phases, and more preferably a primary phase of aluminum titanate, having very low thermal expansion.
  • Aluminum titanate crystals show anisotropy in their thermal expansion. Both crystal structures show expansion of their a- and b-axis under heating and contraction of their c-axis.
  • a broad range of response in thermal expansion for the embodiments of the anisotropic AT-based materials disclosed herein was demonstrated, ranging from a completely negative average coefficient of thermal expansion from room temperature to 800 °C to positive average coefficient.
  • anisotropic AT-based materials disclosed herein can provide a variety of thermal expansion behaviors, absolute values and temperature dependencies, as achieved by using different amounts of fibrous alumina, different sizes of the particulate alumina and different types of pore formers.
  • FIG. 9 is a plot that compares the thermal expansion and contraction during heating and cooling cycle for different materials disclosed herein and shows the wide range of thermal expansion behavior that can be met by these materials.
  • the solid lines represent expansion upon heating, and the dashed lines represent contraction upon cooling.
  • the respective cooling curve (dashed line) corresponding to a given heating curve can be identified at or below the corresponding heating curve (solid line) at 1000 C.
  • Anisotropic microstructures result in an improvement in strength. Comparison of the MOR of honeycomb in (300/14) geometry, and porosity to current art materials and a control specimen that does not have anisotropic microstructure (P2), shows improvement in MOR. Compared to materials made with particulate alumina, materials made from fibrous alumina as raw material exhibit high strength even with very high porosity.
  • FIG. 10 is a plot of MOR of various honeycombs as function of porosity.
  • the materials were made from various types of batch alumina (particulate or fibrous), extruded into honeycomb bodies of 300 cells per square inch and 14 mil (0.014 inch) thick walls, and fired.
  • the honeycomb bodies were made from batches with all particulate alumina ( ⁇ ), F1 alumina fiber ( ⁇ ), F2 alumina fiber ( ⁇ ), F3 alumina fiber (X), or F3 alumina fiber ( ⁇ ).
  • the MOR is greater than 350psi, in other embodiments larger than 380psi and in other embodiments even larger than 400psi for a (300/14) honeycomb geometry.
  • particulate filters such as diesel particulate filters can be made of anisotropic AT-based materials, which provide low pressure drop due to their high porosity of possibly 60% and a high filtration efficiency due to smaller pore size but which would still meet the requested low backpressure.
  • the thermal expansion of an aluminum titanate ceramic is affected by the mixture of the phases and their crystallographic orientation, but also can be lowered by microcracking.
  • the density of the microcracks in a ceramic correlates with the local misorientation between the grains in the microstructure and the local strain build up during cooling.
  • the extreme case that can be considered for a monolithic AT ceramic is a microstructure with grains with very little misorientation that almost behave like a single crystal and does not microcrack and a microstructure with grains with large c - a,b misorientation (c- being the crystallographic axis of aluminum titanate that shows negative coefficient of thermal expansion and a, b showing positive expansion) that would build up high stresses during cooling and induce severe microcracking.
  • stresses during cooling are not only caused by the anisotropy of the expansion of the aluminum titanate phase; secondary phases with their higher coefficient of thermal expansion contribute to the build up of local strain and affect further microcracking of the aluminum titanate grains.
  • aluminum titanate grain size, texture and distribution of primary and secondary phases directly affect the microcrack density in the material and the material's CTE and strength.
  • the materials disclosed herein exhibit differences in microstructure and AT texture compared to known aluminum titanate based materials.
  • the aluminum titanate average grain size ranges from 10-15 micrometers; in aluminum titanate-feldspar composite obtained from 2/3 of particulate alumina raw material with an average particulate size of 10 micrometers and 1/3 of fibrous alumina raw material, the aluminum titanate average grain size ranges from 5-10 micrometers; in aluminum titanate-feldspar composite obtained from fibrous alumina raw material with an average fiber diameter of 3-20 micrometers and 3 mm in length, the aluminum titanate average grain size is smaller than 5 micrometers.
  • Comparative materials disclosed herein that have been made by simple compaction under force show preferential alignment of the raw material alumina fibers in the pressing plane and, in the corresponding fired ware, show a preferential alignment of the c-direction of the primary reaction product aluminum titanate also in this plane.
  • FIG. 11 shows an alumina titanate pole figure for the negative expansion c-axis for material obtained with fibrous alumina raw material.
  • the high intensity in the center of the pole figure for the material obtained from fiber on the honeycomb cross section indicates a strong preferential orientation of the aluminum titanate crystal c-axis in the honeycomb channel direction.
  • the black shading indicates a preferential alignment factor of 3-4.
  • FIG. 12 shows an alumina titanate pole figure for the negative expansion c-axis for material obtained from coarse particulate alumina raw materials, shown for the c-axis of aluminum titanate within space a random distribution, wherein the pole figure is taken in the direction of the aluminum titanate c-axis, which shows essentially no such preferential crystallographic orientation is observed.
  • the corresponding X-ray spectra show differences in the relative intensity in the axial direction from peaks with significant contribution from the aluminum titanate c-axis.
  • aluminum-titanate based ceramics obtained from at least one fibrous raw material exhibit a lower elastic modulus at higher temperatures as compared to aluminum-titanate based ceramics obtained from particulate (only) inorganic ceramic-forming raw materials.
  • the elastic modulus (EMOD) of ceramics obtained from particulates only typically exhibit a strong hysteresis during heating and cooling of the ceramic.
  • the hysteresis for materials obtained with similar batches but with fibrous alumina as raw materials exhibit less hysteresis in the heating-cooling cycle. While the EMOD for a comparative ceramic obtained with particulate coarse alumina and a material obtained from fibrous raw materials was very similar at room temperature i.e.
  • the ratio of EMOD@1000C/EMOD@25C on cooling was larger than 6 for materials obtained from particulate alumina, while the same ratio was less than about 4 for materials derived from fibrous raw material.
  • the materials disclosed herein obtained with fibrous alumina raw material show similar room temperature values as particulate derived materials, and show hysteresis in a heating-cooling cycle, however, the disclosed materials obtained with fibrous raw materials exhibit lower elastic modulus at high temperatures.
  • the improvement in high temperature E-mod can result in an improvement in strain tolerance at high temperature and thus better thermal shock resistance at high temperature, as the combination of improved high temperature MOR, lower high temperature elastic modulus and smaller CTE all contribute to very high thermal shock resistance.
  • porous ceramic body of the present disclosure exhibit high strength and low CTE such as illustrated by the above examples.
  • porous ceramic body of the present disclosure comprise an MOR of greater than 300 psi and a CTE from 20 to 1000°C (in 10 -7 K -1 ) of less than 15, and in some of these embodiments less than 10, and in other of these embodiments less than 5, and in other of these embodiments less than or equal to 5 and greater than or equal to -5.
  • the porous ceramic body comprises an MOR (in psi) of greater than 350 and a CTE from 20 to 1000°C (in 10 -7 K -1 ) of less than 15, and in some of these embodiments less than 10, and in other of these embodiments less than 5, and in other of these embodiments less than or equal to 5 and greater than or equal to -5.
  • porous ceramic body of the present disclosure comprise an MOR of greater than 300 psi for 300/14honeycomb geometry and a CTE from 20 to 800°C of less than 15 x 10 -7 K -1 , and in some of these embodiments less than 10 x 10 -7 K -1 , and in other of these embodiments less than 5 x 10 -7 K -1 , and in other of these embodiments less than or equal to 5 x 10 -7 K -1 and greater than or equal to -5 x 10 -7 K -1 .
  • the porous ceramic body comprises an MOR (in psi) of greater than 350 and a CTE from 20 to 1000°C of less than 15 x 10 -7 K -1 , and in some of these embodiments less than 10 x 10 -7 K -1 , and in other of these embodiments less than 5 10 -7 K -1 , and in other of these embodiments less than or equal to 5 x 10 -7 K -1 and greater than or equal to -5 x 10 -7 K -1 .
  • Some embodiments of the porous ceramic body of the present disclosure comprise a porosity of greater than 60% and an MOR of greater than 150 psi, some greater than 200 psi, some greater than 300 psi, and some even greater than 350 psi.
  • porous ceramic body of the present disclosure comprise a porosity of greater than 64% and an MOR of greater than 150 psi, some greater than 200 psi. Some embodiments disclosure comprise a porosity of greater than 68% and an MOR of greater than 150 psi.
  • a porous ceramic body is provided from batch comprised of greater than 10 % precursor fibers by weight of inorganic raw materials in the batch, the body having an MOR of greater than 300 psi, and in some of these embodiments greater than 350 psi for 300/14honeycomb cell geometry or equivalent.
  • a porous ceramic body is provided from batch comprised of greater than 30 % precursor fibers by weight of inorganic raw materials in the batch, the body having an MOR of greater than 250 psi, and in some of these embodiments greater than 300 psi for 300/14 honeycomb cell geometry or equivalent.
  • a porous ceramic body is provided from batch comprised of greater than 40 % precursor fibers by weight of inorganic raw materials in the batch, the body having an MOR of greater than 250 psi, and in some of these embodiments greater than 300 psi, and in some of these embodiments greater than 350 psi and in some even higher than 400psi for 300/14 honeycomb cell geometry or equivalent.
  • a porous ceramic body is provided from batch comprised of greater than 50 % precursor fibers by weight of inorganic raw materials in the batch, the body having an MOR of greater than 300 psi, and in some of these embodiments greater than 350 psi for 300/14 honeycomb cell geometry or equivalent.
  • a porous ceramic body is made from batch comprised of greater than 10 % precursor fibers by weight of inorganic raw materials in the batch, such that the specific MOR is greater than 700 psi, and in some of these embodiments greater than 800 psi.
  • a porous ceramic body is provided from batch comprised of greater than 40 % precursor fibers by weight of inorganic raw materials in the batch, the body having a specific MOR (in psi) such that the specific MOR is greater than 400 psi, and in some of these embodiments, greater than 500 psi, greater than 600 psi, greater than 700 psi, greater than 800 psi, and even greater than 900 psi.
  • a porous ceramic body is provided from batch comprised of greater than 50 % precursor fibers by weight of inorganic raw materials in the batch, such that the specific MOR is greater than 400 psi, and in some of these embodiments, greater than 500 psi, greater than 600 psi, greater than 700 psi, and even greater than 800 psi.
  • a porous ceramic body is provided from batch comprised of greater than 55 % precursor fibers by weight of inorganic raw materials in the batch, such that the specific MOR is greater than 400 psi, and in some of these embodiments, greater than 500 psi, greater than 600 psi, greater than 700 psi, and even greater than 800 psi.
  • the porous ceramic body exhibits a value of (d50-d10)/d50 of less than 1.00, and in some of these embodiments, less than 0.90, and in others less than 0.70. In some embodiments, (d50-d10)/d50 is greater than 0.25 and less than 0.90. In other embodiments, (d50-d10)/d50 is less than 0.6. In still other embodiments, (d50-d10)/d50 is less than 0.35.
  • the porous ceramic body exhibits a value of (d90-d10)/d50 of less than 5.0, and in some of these embodiments, less than 3.0, and in others less than 2.0. In some embodiments, (d90-d10)/d50 is greater than 0.5 and less than 3.00.
  • the porous ceramic body exhibits a tortuosity of less than 20, and in some of these embodiments, less than 15. In other embodiments, the porous ceramic body exhibits a tortuosity of less than 20, and in some of these embodiments, less than 15. In other embodiments, the porous ceramic body exhibits a tortuosity of greater than 2, and in some of these embodiments, greater than 5. In some embodiments, the tortuosity is greater than 5 and less than 15.
  • Table 14 shows crystalline phases and glass in fired compositions.
  • Table 14 Example No. P2 CT1 PT1 PT2 B5 B4 CT3 CT4 C17 % aluminum titanate 73 72 73.2 72.1 72.8 72.8 72.8 71.4 61.4 % Feldspar 21 23 20.6 21.3 20.6 20.6 21.4 21.4 17.8 % Rutile 0.2 0.5 0.7 0.7 0.9 0.7 1.7 2 0.6 % Mullite 2.6 % Alumina 5.4 2.2 5.6 5.9 5.7 6
  • Table 15 lists various examples of ceramic compositions having microstructure anisotropy. Examples C4 and P2 were extruded via ram, while the remaining examples in Table 15 were extruded via twin screw.
  • Table 15 CT1 C4 CT3 CT4 P4 P2 PT1 POROSITY d50pore-long-extrdir in ⁇ m 29.1 25.7 26.8 26.4 26.4 21.6 24.7 d50pore-long-perpextrdir in ⁇ m 22.5 16.3 18.42 19.6 23.8 19.7 21.9 Af-pore-long 1.29 1.58 1.45 1.34 1.11 1.10 1.13 d50pore-cross-dir1 in ⁇ m 18.7 16.6 19.4 19.0 20.5 17.4 22.3 d50pore-cross-dir2 in ⁇ m 19.7 18.5 22.8 22.2 23.5 19.7 25.0 Af-pore-cross 0.95 0.90 0.85 0.86 0.86 0.88 0.89 MATTER d50matter-long-extrdir in ⁇ m 20.6 17.6 26.2 d50m
  • a porous ceramic body comprised of a polycrystalline ceramic comprising an anisotropic microstructure is characterized by an anisotropy factor, Af-pore-long, wherein 1.2 ⁇ Af-pore-long ⁇ 5; in some embodiments, 1.25 ⁇ Af-pore-long ⁇ 3.
  • a porous ceramic body comprised of a polycrystalline ceramic comprising an anisotropic microstructure is characterized by an anisotropy factor, Af-matter-long, wherein 1.2 ⁇ Af-matter-long ⁇ 5; in some embodiments, 1.25 ⁇ Af-matter-long ⁇ 3.
  • a porous ceramic body comprised of a polycrystalline ceramic comprising an anisotropic microstructure is characterized by a first anisotropy factor, Af-pore-long, a second anisotropy factor, Af-pore-cross, a third anisotropy factor, Af-matter-long, and a fourth anisotropy factor, Af-matter-cross, wherein 5>Af-pore-long > 1.2 and 5>Af-matter-long > 1.2.
  • a porous ceramic body comprised of a polycrystalline ceramic comprising an anisotropic microstructure is characterized by a first anisotropy factor, Af-pore-long, a second anisotropy factor, Af-pore-cross, a third anisotropy factor, Af-matter-long, and a fourth anisotropy factor, Af-matter-cross, wherein 3>Af-pore-long > 1.25 and 3>Af-matter-long > 1.3.
  • the ceramic is characterized by an anisotropy of its spatial porosity distribution with 1.25 ⁇ Af-pore-long ⁇ 3 with 0.9 ⁇ Af-pore-cross ⁇ 1.1 and an anisotropy of its spatial matter distribution with 1.2 ⁇ Af-matter-long ⁇ 3 with 0.85 ⁇ Af-matter-cross ⁇ 1.15.
  • Porous aluminum titanate-based honeycomb ceramic articles can be made with materials disclosed herein that combine low thermal expansion, high porosity, low Young modulus and high strength, and are attractive for catalyst substrate (e.g. automotive catalytic converter) and filter (e.g. particulate filter or diesel particulate filter) applications.
  • catalyst substrate e.g. automotive catalytic converter
  • filter e.g. particulate filter or diesel particulate filter
  • raw materials such as alumina, titania and raw materials for forming the second phase, for example such as strontium oxide, silica to form feldspar can be mixed with organic binders pore formers and water to form a plasticized or plastic mixture.
  • the plastic mixture is extruded or otherwise shaped into the desired form, known in the industry as a "green body.” Shaping can be achieved by extruding the mixed raw materials through a die. The green body can then be dried and then fired (e.g. to temperatures of about 1350° C to about 1450°C, depending on the raw material combination). During the drying and firing process, the raw materials react, and may pass through various intermediates, into the final crystalline alumina titanate composite. The shaped green part transforms upon sintering into a solid, durable ceramic article.
  • the primary solid phase of the ceramic exhibits strong crystallographic texture of an aluminum titanate phase with a strong preferential alignment of the crystallographic c-axis of aluminum titanate in the extrusion direction (or perpendicular to the pressing direction when only pressed)
  • Filters such as diesel particulate filters (DPF) can be obtained from a honeycomb porous ceramic by plugging channels (e.g. neighboring channels in a checkerboard pattern, such as on both ends) to form a filter with inlet and outlet channels.
  • the exhaust gas has then to flow through the wall of the honeycomb.
  • small particulates from the exhaust gas are deposited on the pore surface, thus providing filtering of the exhaust gas.
  • the forming soot cake is periodically burned in a regeneration cycle, e.g. so that a DPF has a lifetime similar to that of the vehicle.
  • Particulate filters such as diesel particulate filters (DPF)
  • DPF diesel particulate filters
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure characterized by an anisotropy factor, Af-pore-long, wherein 1.2 ⁇ Af-pore-long ⁇ 5. In some embodiments, 1.25 ⁇ Af-pore-long ⁇ 3.
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure characterized by an anisotropy factor, Af-matter-long, wherein 1.2 ⁇ Af-matter-long ⁇ 5. In some embodiments, 1.25 ⁇ Af-matter-long ⁇ 3.
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure characterized by a first anisotropy factor, Af-pore-long, a second anisotropy factor, Af-pore-cross, a third anisotropy factor, Af-matter-long, and a fourth anisotropy factor, Af-matter-cross, wherein 5>Af-pore-long > 1.2 and 5>Af-matter-long > 1.2.
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure characterized by a first anisotropy factor, Af-pore-long, a second anisotropy factor, Af-pore-cross, a third anisotropy factor, Af-matter-long, and a fourth anisotropy factor, Af-matter-cross, wherein 3>Af-pore-long > 1.25 and 3>Af-matter-long > 1.3.
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure characterized by a first anisotropy factor, Af-pore-long, a second anisotropy factor, Af pore-cross, a third anisotropy factor, Af-matter-long, and a fourth anisotropy factor, Af-matter-cross, wherein 1.25 ⁇ At-pore-long ⁇ 3 and 0.9 ⁇ Af-pore-cross ⁇ 1.1.
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure characterized by a first anisotropy factor, Af-pore-long, a second anisotropy factor, Af-pore-cross, a third anisotropy factor, Af-matter-long, and a fourth anisotropy factor, Af-matter-cross, wherein 1.2 ⁇ Af-matter-long ⁇ 3 and 0.85 ⁇ Af-matter-cross ⁇ 1.15.
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure characterized by a first anisotropy factor, Af-pore-long, a second anisotropy factor, Af-pore-cross, a third anisotropy factor, Af-matter-long, and a fourth anisotropy factor, Af-matter-cross, wherein 1.25 ⁇ Af-pore-long ⁇ 3 and 0.9 ⁇ Af-pore-cross ⁇ 1.1, and 1.2 ⁇ Af-matter-long ⁇ 3 and 0.85 ⁇ Af-matter-cross ⁇ 1.15.
  • a porous ceramic body is comprised of a polycrystalline ceramic comprising an anisotropic microstructure, the anisotropic microstructure being comprised of aligned multiphase polycrystalline reticular formations.
  • the reticular formations are comprised of a primary solid phase and at least minor solid phase.
  • the microstructure further comprises non-aligned formations.
  • the microstructure contains microcracks.
  • the microstructure has an anisotropy factor 5 > Af-pore-long > 1.2.
  • the microstructure has an anisotropy factor 3 >Af-pore-long > 1.2.
  • the microstructure has an anisotropy factor 5 >Af-matter-long > 1.2. In some embodiments, the microstructure has an anisotropy factor 3 >Af-matter-long > 1.2. In some embodiments, the microstructure has anisotropy factors Af-pore-long and Af-matter-long, and 5 >Af-pore-long > 1.25 and 5 >Af-matter-long > 1.3. In some embodiments, the microstructure has anisotropy factors Af-pore-long and Af-matter-long, and 3 >Af-pore-long > 1.25 and 3 >Af-matter-long > 1.3.
  • the microstructure has anisotropy factors Af-pore-long and Af-pore-cross, and 1.25 ⁇ Af-pore-long ⁇ 3 and 0.9 ⁇ Af-pore-cross ⁇ 1.1. In some embodiments, the microstructure has anisotropy factors Af-matter-long and Af-matter-cross, and 1.2 ⁇ Af-matter-long ⁇ 3 and 0.85 ⁇ Af-matter-cross ⁇ 1.15.
  • the microstructure has anisotropy factors Af-pore-long, Af-pore-cross, Af-matter-long, and Af-matter-cross, and 1.25 ⁇ Af-pore-long ⁇ 3 and 0.9 ⁇ Af-pore-cross ⁇ 1.1, and 1.2 ⁇ Af-matter-long ⁇ 3 and 0.85 ⁇ Af-matter-cross ⁇ 1.15.
  • the reticular formations are polycrystalline. In some embodiments, the crystals have a maximum dimension of between 0.5 and 100 micrometers. In some embodiments, a majority of the primary phase crystals have a maximum dimension of between 1 and 50 micrometers. In some embodiments, a majority of the primary phase crystals have a maximum dimension of between 1 and 10 micrometers. In some embodiments, the reticular formations constitute greater than 5% by weight of the body. In some embodiments, the reticular formations constitutes between 5% and 60% by weight of the body. In some embodiments, the reticular formations constitute more than 60% by weight of the body.
  • the reticular formations are comprised of a primary solid phase and at least one minor solid phase.
  • the primary solid phase is aluminum titanate.
  • the minor solid phase is selected from the group consisting of feldspar, mullite, cordierite, spinel, strontium titanate, and combinations thereof.
  • the minor solid phase is selected from the group consisting of oxides of aluminum, titanium, silicon, magnesium, alkaline earth metals, rare earth metals, alkali metals, transition metals, or combinations thereof.
  • the first minor phase is selected from the group consisting of feldspar, mullite, spinel, strontium titanate, and combinations thereof.
  • the second minor phase is selected from the group consisting of oxides of aluminum, titanium, silicon, magnesium, alkaline earth metals, rare earth metals, alkali metals, transition metals, or combinations thereof.
  • exterior regions of at least some of the reticular formations are comprised of a primary solid phase and an interior region of the reticular formations are comprised of a minor solid phase.
  • the minor solid phase is comprised of a ceramic-forming precursor.
  • the minor solid phase is selected from the group consisting of oxides of aluminum, titanium, silicon, magnesium, alkaline earth metals, rare earth metals, alkali metals, transition metals, or combinations thereof.
  • the reticular formations are comprised of a primary solid phase of aluminum titanate.
  • the microstructure further comprises multiphase polycrystalline clump formations.
  • the porous body has a porosity of greater than 40%, or greater than 50%, or greater than 55%, or greater than 60%, or even greater than 65%.
  • the porous body comprises pores having a median pore size of greater than 10 micrometers. In some embodiments, the porous body comprises pores having a median pore size of larger than 5 micrometers. In some embodiments, the porous body comprises pores having a median pore size of less than 10 micrometers. In some embodiments, the porous body comprises pores having a median pore size of less than 20 micrometers. In some embodiments, the porous body comprises pores having a median pore size of greater than 10 and less than 20 micrometers.
  • the porous body has an average CTE having a magnitude less than 25 x 10 -7 K -1 in the temperature range from 20°C to 1000°C. In some embodiments, the porous body in an axial direction has an average CTE having a magnitude less than 5 x 10 -7 K -1 for all temperatures in the temperature range from 20°C to 1000°C. In some embodiments, the body in an axial direction has a negative average coefficient of thermal expansion in the temperature range from 20°C to 1000°C. In some embodiments, the porous body has in an axial direction an elastic modulus of less than 1,400,000 psi for all temperatures from 20 °C to 1200°C.
  • the porous body has in an axial direction an elastic modulus of less than 300,000psi at 20° C. In some embodiments, the porous body exhibits a ratio of EMOD 1000C /EMOD 20C ⁇ 5 in an axial direction, a radial direction, or both. In some embodiments, the porous body has a wall strength greater than 3 MPa. In some embodiments, the porous body has a wall strength greater than 5 MPa. In some embodiments, the porous body has a wall strength greater than 8 MPa. In some embodiments, the porous honeycomb has an MOR greater than 300psi in (300/14) cell geometry, or greater than 350 psi, or even greater than 400 psi.
  • the porous body is in the form of a honeycomb structure.
  • the porous body is a wall flow filter or a flow through substrate.
  • the porous body is comprised of aluminum titanate.
  • the porous body has a strain tolerance of greater than 0.10%. In some embodiments, the porous body exhibits a thermal shock parameter TSP of at least about 1250°C. In some embodiments, the porous body has a permeability of at least 500 mDarcy.
  • an inorganic composition is comprised of an anisotropic microstructure comprising the reaction product of a plurality of ceramic-forming precursors, wherein the reaction product is present as polycrystalline multiphase reticular formations.
  • a method for forming a porous body comprised of a first ceramic phase of aluminum titanate comprising: forming a plasticized mixture comprising a plurality of inorganic ceramic-forming precursors including a first precursor, wherein at least part of the first precursor is present in the mixture in the form of precursor fibers; shaping the plasticized mixture into a green body; and heating the green body sufficient to cause the precursors to react together to produce the first ceramic phase.
  • the polycrystalline reticular formations are polycrystalline multiphase reticular formations.
  • at least some of the first precursor is present in the mixture in the form of non-fibrous particles.
  • the plurality of inorganic ceramic-forming precursors further comprises a second precursor, wherein at least part of the second precursor is present in the mixture in the form of second precursor fibers, wherein the second precursor is different from the first precursor.
  • the first precursor is alumina and the second precursor is silica.
  • the plurality of inorganic ceramic-forming precursors further comprises a second precursor, wherein at least some of the precursor fibers contain both the first precursor and the second precursor.
  • the mixture further comprises a ceramic material.
  • the ceramic material is comprised of the first ceramic phase material.
  • a reactive portion of the precursor fibers reacts during the heating to form the first ceramic phase material, and wherein an excess portion of the precursor fibers does not react during the heating to form the first ceramic phase material. In some embodiments, at least some of the excess portion is disposed in an interior region of at least some of the reticular formations.
  • no precursor fibers are present in the ceramic body.
  • all of the first precursor present in the mixture is in the form of the precursor fibers.
  • the first ceramic constitutes a primary solid phase in the ceramic body. In some embodiments, the first ceramic constitutes a primary solid phase in the reticular formations.
  • the precursor fibers have an average length of from 1 to 10 mm. In some embodiments, the precursor fibers have an average diameter of from 1 to 100 micrometers. In some embodiments, the precursor fibers have an average length to diameter ratio of from 100:1 to 10,000:1.
  • the shaping comprises extruding the plasticized mixture into a green body.
  • the extruding comprises extruding the mixture through a first die to form a first extrudate, and then extruding the first extrudate through a second die to form a honeycomb shape.
  • the plurality of inorganic ceramic-forming precursors further comprises at least one source of silica, alumina, magnesium oxide, strontium oxide, barium oxide, calcium oxide, titania, or iron oxide. In some embodiments, the plurality of inorganic ceramic-forming precursors further comprises a source of alumina and a source of silica. In some embodiments, the plurality of inorganic ceramic-forming precursors further comprises a source of magnesia. In some embodiments, the mixture further comprises at least one organic processing component. In some embodiments, the mixture further comprises at least one processing component selected from the group consisting of binders, lubricants, plasticizers, pore formers and solvents.
  • the mixture comprises from 3 wt% to 12 wt% silica, based on total weight of the mixture. In some embodiments, the mixture comprises from 25 wt% to 54 wt% SiO 2 , based on total weight of the mixture. In some embodiments, the mixture comprises from 10 wt% to 70 wt% alumina, based on total weight of the mixture. In some embodiments, the mixture comprises from 18 wt% to 65 wt% Al 2 O 3 , based on total weight of the mixture. In some embodiments, the mixture comprises from 25 wt% to 50 wt% titania, based on total weight of the mixture.
  • the mixture comprises from 10 wt% to 65 wt% alumina fibers, based on total weight of the mixture. In some embodiments, the mixture comprises from 5 wt% to 23 wt% MgO, based on total weight of the mixture.
  • the precursor fibers constitute from 18 wt% to 48 wt% alumina, based on total weight of the mixture. In some embodiments, the precursor fibers constitute at least 75 wt% alumina, based on total weight of the mixture. In some embodiments, at least part of the first ceramic is comprised of an anisotropic microstructure comprised of polycrystalline reticular formations, and wherein at least some of the precursor fibers serve as templates for the reticular formations.
  • a porous ceramic body having a total porosity of greater than or equal to 50%, an coefficient of thermal expansion (CTE) of less than 2 x 10 -7 K -1 from 20 °C to 900 °C, a strain tolerance of greater than or equal to 0.10 %, and an MOR > 350 psi for a 300/14 honeycomb or corresponding geometry.
  • the axial CTE is less than 0.5 x10 -7 K -1 .
  • the axial CTE is negative.
  • the total porosity is greater than 60%.
  • the body has a d50 between 12 and 20 micrometers. In some embodiments, the body has a d50 between 15 and 20 micrometers.
  • a porous ceramic body having a total porosity of greater than or equal to 55%, a d50 > 12 micrometers, coefficient of thermal expansion (CTE) of less than 2 x 10 -7 K -1 from 20 °C to 900 °C, a strain tolerance of greater than or equal to 0.10 %, and an MOR > 350psi.
  • CTE coefficient of thermal expansion
  • a porous ceramic body having a total porosity of greater than or equal to 55%, an MOR > 350psi, and a d50 between 15 and 20 micrometers.

Claims (13)

  1. Corps céramique poreux, formé par extrusion et ayant un axe d'extrusion, le corps étant composé d'une céramique polycristalline comprenant des grains de titanate d'aluminium, les grains de titanate d'aluminium ayant une texture cristallographique avec un alignement cristallographique préférentiel, l'axe cristallographique c étant un axe de dilatation négative et l'axe a et l'axe b présentant une dilatation positive, et l'axe c du titanate d'aluminium s'alignant préférentiellement dans la direction de l'extrusion du corps céramique poreux formé par extrusion, et la céramique polycristalline ayant une microstructure anisotrope caractérisée par un facteur d'anisotropie, Af-pore-long, où 1,2 < Af-pore-long < 5, Af-pore-long étant un facteur d'anisotropie pour la distribution des pores d'une section longue de paroi polie d'une pièce en nid d'abeilles cuite, extrudée dans une direction d'extrusion, Af-pore-long étant égal à un rapport d50pore-long-extrdir/d50pore-long-perpextrdir qui est la longueur moyenne des pores dans la direction d'extrusion divisée par la longueur moyenne des pores dans la direction perpendiculaire à l'extrusion.
  2. Corps céramique poreux selon la revendication 1 dans lequel 1,25 < Af-pore-long < 3.
  3. Corps céramique poreux selon la revendication 1, comprenant en outre un deuxième facteur d'anisotropie, Af-pore-trans, un troisième facteur d'anisotropie, Af-matière-long, et un quatrième facteur d'anisotropie, Af-matière-trans, où 1,25 < Af-pore-long < 3 et 0,9 < Af-pore-trans < 1,1, et 1,2 < Af-matière-long < 3 et 0,85 < Af-matière-trans < 1,15, Af-pore-trans étant le rapport d50pore-trans-dir1/d50pore-trans-dir2, qui est la longueur moyenne des pores dans une première direction en coupe transversale divisée par la longueur moyenne des pores dans une deuxième direction en coupe transversale, Af-matière-long étant un facteur d'anisotropie pour la distribution de matière de la section longue de paroi polie de la pièce en nid d'abeilles cuite, extrudée dans la direction d'extrusion, Af-matière-long étant égal à un rapport d50matière-long-extrdir/d50matière-trans-perpextrdir, qui est la longueur moyenne de la matière dans la direction d'extrusion divisée par la longueur moyenne de la matière dans la direction perpendiculaire à l'extrusion, et Af-matière-trans étant le rapport d50matière-trans-dir1/d50matière-trans-dir2, qui est la longueur moyenne de la matière dans la première direction en coupe transversale divisée par la longueur moyenne de la matière dans la deuxième direction en coupe transversale.
  4. Corps céramique poreux selon la revendication 1, dans lequel la microstructure anisotrope est composée de formations réticulaires polycristallines multiphasées alignées.
  5. Corps poreux selon la revendication 4 dans lequel la microstructure contient des microfissures.
  6. Corps poreux selon la revendication 4 dans lequel les formations réticulaires comprennent des cristaux ayant une dimension maximale comprise entre 0,5 et 100 micromètres.
  7. Corps poreux selon la revendication 4 dans lequel les formations réticulaires sont composées d'une phase solide principale de titane d'aluminium et d'au moins une phase solide mineure, la phase solide principale comprenant des cristaux de phase principale, et une majorité des cristaux parmi les cristaux de phase principale ayant une dimension maximale comprise entre 1 et 50 micromètres.
  8. Corps poreux selon la revendication 4, le corps étant composé d'une phase solide principale de titane aluminium.
  9. Corps poreux selon la revendication 4 dans lequel la phase solide mineure est choisie dans le groupe constitué par le feldspath, la mullite, la cordiérite, le spinelle, le titanate de strontium, et les combinaisons de ceux-ci.
  10. Corps poreux selon la revendication 4 dans lequel une région extérieure d'au moins certaines des formations réticulaires est composée d'une phase solide principale et une région intérieure des formations réticulaires est composée d'une phase solide mineure.
  11. Corps céramique poreux selon la revendication 1, le corps ayant une porosité de plus de 50 %, ou plus de 60 %, ou plus de 65 %.
  12. Corps poreux selon la revendication 4 dans lequel les formations réticulaires sont composées d'une phase solide principale de titanate d'aluminium et d'au moins une phase solide mineure.
  13. Corps poreux selon la revendication 4, les formations réticulaires constituant plus de 5 % en poids du corps.
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Families Citing this family (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070107395A1 (en) 2005-11-16 2007-05-17 Bilal Zuberi Extruded porous substrate and products using the same
US7959704B2 (en) * 2005-11-16 2011-06-14 Geo2 Technologies, Inc. Fibrous aluminum titanate substrates and methods of forming the same
US7960009B2 (en) * 2008-02-29 2011-06-14 Corning Incorporated Dispersion-toughened cordierite for filter and substrate applications
FR2933399B1 (fr) * 2008-07-04 2011-02-18 Saint Gobain Ct Recherches Melange de grains pour la synthese d'une structure poreuse du type titanate d'alumine
JP5231304B2 (ja) * 2009-03-26 2013-07-10 日本碍子株式会社 アルミナ質多孔体及びその製造方法
KR20120027112A (ko) * 2009-03-30 2012-03-21 스미또모 가가꾸 가부시끼가이샤 티탄산 알루미늄계 세라믹스체의 제조 방법
US20110124486A1 (en) * 2009-11-24 2011-05-26 Bonham Christine Gallaher Aluminum Titanate-Containing Ceramic-Forming Batch Materials And Methods Using The Same
US8148297B2 (en) * 2009-11-30 2012-04-03 Corning Incorporated Reticular cordierite composition, article and manufacture thereof
CN101805199B (zh) * 2010-03-31 2013-12-04 周绍春 一种钛酸铝纳米纤维增韧氧化铝复合材料及其制备方法
WO2012030610A1 (fr) 2010-08-30 2012-03-08 Corning Incorporated Fibre bi-composante chargée de particules, et procédé de fabrication
US8517184B2 (en) * 2010-09-30 2013-08-27 Baker Hughes Incorporated Anisotropic filtration media
US9272956B2 (en) * 2011-05-27 2016-03-01 Corning Incorporated Method for controlling aluminum titanate ceramic filter properties
EP2855722A1 (fr) 2012-05-31 2015-04-08 Zimmer, Inc. Échafaudages poreux anisotropes
US9126871B2 (en) 2012-05-31 2015-09-08 Corning Incorporated Carbonates as relic pore formers in aluminum titanate
CN103025043A (zh) * 2012-12-13 2013-04-03 江苏达胜加速器制造有限公司 一种瓷环的处理工艺
US9623360B2 (en) 2013-05-20 2017-04-18 Corning Incorporated Porous ceramic article and method of manufacturing the same
US9376347B2 (en) 2013-05-20 2016-06-28 Corning Incorporated Porous ceramic article and method of manufacturing the same
US9908260B2 (en) * 2013-05-20 2018-03-06 Corning Incorporated Porous ceramic article and method of manufacturing the same
WO2015046242A1 (fr) 2013-09-24 2015-04-02 日立金属株式会社 Structure céramique en nid d'abeille à base de cordiérite et son procédé de production
EP2980049B1 (fr) 2013-09-24 2017-06-07 Hitachi Metals, Ltd. Structure céramique en nid d'abeilles et son procédé de production
US9416056B2 (en) * 2014-05-30 2016-08-16 Corning Incorporated Isolated pseudobrookite phase composites and methods of making
EP3275853B1 (fr) 2015-03-24 2020-04-22 Hitachi Metals, Ltd. Structure céramique en nid d'abeilles
EP3275541B1 (fr) 2015-03-24 2023-02-15 Hitachi Metals, Ltd. Structure en nid d'abeilles en céramique
EP3275852B1 (fr) 2015-03-24 2022-01-12 Hitachi Metals, Ltd. Structure céramique en nid d'abeille et son procédé de fabrication
CN109219589B (zh) 2016-05-31 2022-04-26 康宁股份有限公司 多孔制品及其制造方法
CN106711049B (zh) * 2016-12-22 2020-09-29 武汉华星光电技术有限公司 一种多孔基板及其制作方法、薄膜晶体管的制作方法
CN106756187B (zh) * 2016-12-16 2018-05-29 西安理工大学 一种以稻谷壳造孔剂制备多孔钛材料的粉末冶金法
JP6693477B2 (ja) * 2017-06-13 2020-05-13 株式会社デンソー 排ガス浄化フィルタ
US11591265B2 (en) 2017-10-31 2023-02-28 Corning Incorporated Batch compositions comprising pre-reacted inorganic particles and methods of manufacture of green bodies therefrom
KR102441367B1 (ko) * 2020-08-06 2022-09-06 희성촉매 주식회사 고기공 담체 상에 촉매 활성 물질 차단 박층이 구비된 배기가스 정화용 촉매
CN115925443B (zh) * 2022-12-30 2023-07-04 中南大学 一种具有宽烧成范围的固废基陶瓷膜支撑体原料及固废基陶瓷膜支撑体

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59186623A (ja) 1983-03-14 1984-10-23 Bridgestone Corp 排ガス浄化フイルタ−
US5213737A (en) * 1991-12-02 1993-05-25 Corning Incorporated Extrusion method and apparatus for producing a body from powder material
WO2000076939A1 (fr) * 1999-06-11 2000-12-21 Corning Incorporated Corps de cordierite tres poreux, tres resistant, et se dilatant faiblement
US7052532B1 (en) 2000-03-09 2006-05-30 3M Innovative Properties Company High temperature nanofilter, system and method
JP2002114583A (ja) * 2000-09-29 2002-04-16 Dainippon Jochugiku Co Ltd 多孔質セラミックス成形品
JP4373177B2 (ja) * 2003-10-22 2009-11-25 日本碍子株式会社 ハニカム構造体、その製造方法及びキャニング構造体
JP4358662B2 (ja) 2004-03-23 2009-11-04 日本碍子株式会社 コーディエライト質ハニカム構造体の製造方法
US7259120B2 (en) * 2004-04-21 2007-08-21 Corning Incorporated Aluminum titanate ceramic articles and methods of making same
US20070259769A1 (en) 2005-02-22 2007-11-08 Ellison Adam J G Aluminum titanate ceramic articles and methods of making same
EP1852406A3 (fr) 2006-05-01 2008-08-06 Ibiden Co., Ltd. Corps à structure en nids d'abeilles, son procédé de fabrication, filtre en nids d'abeille et son procédé de fabrication
US7923093B2 (en) * 2006-06-30 2011-04-12 Corning Incorporated High porosity filters for 4-way exhaust gas treatment
WO2008096413A1 (fr) 2007-02-06 2008-08-14 Ibiden Co., Ltd. Structure en nid d'abeilles

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US8119234B2 (en) 2012-02-21
CN102015576A (zh) 2011-04-13
JP5572102B2 (ja) 2014-08-13
JP2011516371A (ja) 2011-05-26
EP2250140A1 (fr) 2010-11-17
US20090220734A1 (en) 2009-09-03
PL2250140T3 (pl) 2016-01-29
CN102015576B (zh) 2014-04-09
WO2009108299A1 (fr) 2009-09-03

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